In the past, a number of different collapsible frames have been provided for collapsible shelters, however, none of these includes a hollow smoke stack unit which is readily collapsible within the confines of the collapsed supporting legs while providing a guide for the operating linkage which controls the collapsing and expansion of the leg structure. Such a prior art structure is shown in my previously issued U.S. Pat. No. 3,008,477, granted November 14, 1961.